EGU21-16503
https://doi.org/10.5194/egusphere-egu21-16503
EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

The Role of Sublimation on the Surface Mass Balance of the Interior Greenland Ice Sheet

Laura Dietrich1, Hans Christian Steen-Larsen1, Cécile Agosta2, Xavier Fettweis3, Anne-Katrine Faber1, and Sonja Wahl1
Laura Dietrich et al.
  • 1University of Bergen, Geophysical Institute and Bjerknes Centre for Climate Research, Bergen, Norway
  • 2Laboratoire des Sciences du Climat et de l'Environnement, LSCE-IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur- Yvette, France
  • 3Department of Geography, UR SPHERES, University of Liège, Liège, Belgium

Precipitation along with sublimation and deposition are the main contributors to the surface mass balance (SMB) in the accumulation area of the Greenland Ice Sheet (GrIS). However, precipitation events are rare and intermittent. In between precipitation events the surface snow continuously undergoes sublimation and deposition. Recent studies imply that these surface exchange processes influence the isotopic composition of the surface snow which is later archived as a climate record in ice cores. In order to understand the possible implications on the recorded climate signal, sublimation needs to be quantified on a local scale.

Here we present simulated SMB components for eight ice core drilling sites on the GrIS using the regional climate model MAR (Modèle Atmosphérique Régional). We validated MAR against in-situ flux observations at the East Greenland Ice Core Project site and found a high sensitivity of sublimation to the downward long wave flux and to the parameterization of the surface roughness length. We propose a surface roughness length optimized for the interior of the GrIS which is supported by our observations.

Our results show that in the GrIS accumulation area the mass turnover via sublimation and deposition can reach the same order of magnitude as precipitation. This highlights the importance of a better understanding of how the climate signal is imprinted in the surface snow isotopic composition.

How to cite: Dietrich, L., Steen-Larsen, H. C., Agosta, C., Fettweis, X., Faber, A.-K., and Wahl, S.: The Role of Sublimation on the Surface Mass Balance of the Interior Greenland Ice Sheet, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16503, https://doi.org/10.5194/egusphere-egu21-16503, 2021.

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